Caribbean Biogeography: Implications of Recent Plate Tectonic Studies

Abstract

Two opposing hypotheses for the origin of the Caribbean terrestrial biota are currently being debated (Rosen, 1975; MacFadden, 1980, 1981; Pregill, 1981b). The vicariance model (Rosen, 1975) proposes that the present Caribbean biota is the result of a fragmented ancestral biota that occupied a proto-Antillean situated between North and South America during the Mesozoic. The fragmentation occurred when a portion of the eastern Pacific seafloor began moving eastward along two major faults, carrying the archipelago with it. The islands and their biota moved to their present location during the late Mesozoic and Cenozoic. The classical theory, proposed prior to the general acceptance of continental drift, suggests that the Caribbean terrestrial biota colonized the islands by dispersal (Matthew, 1918; Richards, 1937; Simpson, 1956; Darlington, 1957; Pregill,